No, wrong comparison. ISIS has never had an Arabic identity, from the beginning an Islamist agenda. Pkk, found by a kurd, with Kurdish agenda for Kurdish identity. That some Kurds has Armenian roots doesn’t change this fact. Turkey, Syria, Iraq, Iran, all the connected organization fight for Kurdish interests.
Islamism and Communism are an international movement. They may have some form of nationalism in their local regions but overall its about appealing to the whole world. For Islamists like isis or al qaeda its about Sharia and the Caliphate. While for communists its all about revolution and the power of the workers how their struggle is a class one not race or any ethnic group.
Then again pkk in my opinion are ideology sluts as their ideology used to be marxism and communism now they seem to follow wide range of ideologies its even said their leader ocalan has abandoned communism.